Burner



Jul'y 1929.

T. E. MURRAY ET Ax. 1.720.089

n BURNER Filed April 22, 1925 2 sheets-sheet 1 l/tfz :L u 70 I I I l l i i V l July 9, 1929- T. E. MURRAY ET Al. I 1.720.089 u BURNER Filed April 22, 1925 i 2 sheets-shea 2 Patented July 9, 1929A.

y UNITED STATES. PATENT OFFICE'.

THOMAS E. MURRAY, OF BROOKLYN, AND JOHN H. LAWRENCE, F NEWl YORK, N. Y.;

' SAID LAWRENCE ASSIGNOR TO SAID MURRAY.

BURNER.

Application.l led April 22,

Our invention aims to provide an improved form of burner for boiler furnaces and similar furnaces using powdered coal, oil or gas or other fuel which is introduced in jets. v

In a previous Murray application Ser. No. 642,725, there is described a boiler, the furnace of which is surrounded by a water wall composed of vertical tubes spaced apart, with overlapping flanges in the spaces so as to secure a wide exposure of heating surface in proportion to the volume of water circulating through the tubes; such boilers being designed for high at a very high rating, that is,' generating steam in excessively large quantity per hour, in p roportion to the square feet of heating surface. Such operation is facilitated greatly by the exposure of the Water wall described to .the direct radiantfheat of the burning fuel. 'The 'burner of the presentl invention is particularly useful in connection with the furnaces of suchl boilers, being designed to distribute the burning fuelN throughout the combustion chamber to better leffect than the ordinarypburners.

The accompanying drawings illustrate embodiments ofthe invention.

Fig. 1 is a longitudinal vertical section of a boiler and furnace with our improvement applied thereto; y A

Fig. 2 is a horizontal section of the same.;

Fig. 3 isa section similar to Fig. 1 showy ing a modification. j

' construction.

Referring to the embodiments of the invention illustrated, the combustion chamber is surrounded by a'water wall composed of vertical tubes 1 spaced apart with overlapping flanges 2 closing the spaces between them and welded to the tubes as explained in the Murray application cited above. Outside of this is a wall of sheet metal 3 and a layer 4 of insulating material. The outer wall may be of any otherusual or suitable The vertical tubes described are `connected at their lower ends to headers 5 and at their upper ends to headers 6 and are in communication with the regular circulating system of the boiler. These tubes may be surmounted by additional sets of f inclined tubes' 7 connected at their ends to vertical headers 8 and 9 which in turn com-. municate with the steam drum 10. .The side walls extend below the vertical tubes in the form of supplementary walls 11 of firepressure and for operating vply of air.

varea during the 1925. Serial No. 24,922.

brick or the like which extend also above the lower headers 5 and the lower ends of the tubes 1 so as to shield such headers and Joints. The bottom of the furnace madeof refractory material is indicated at 12 and at the center of the floor and covering a large part of its area is the arrangement which as a whole we have referred to as the burner. A floor 13 of steel, concrete or other material is located outside the refractory material. j

Nozzles 15 are located in the central portion of the concave r depressed portion of the floor, for introduction vof a mixture of air and powdered coal and may be provided `with a spiral rib 16 for causing a swirling A- number of nozzles 15 is arranged in line l across the width of the furnace asV indicated in dotted lines in Fig. 2. The 'concave portion of the floor is provided with a lining 17 of refractory material; preferably openings 18 are provided in lines adjacent to the line of nozzles 15 for admitting a secondary sup- The lining 17 may be made of carborundum or other highly refractory bricks. For `greater resistance to the heat there 'may be embedded in this lining watercirculating tubes 19. These tubes are shown projecting iniFig. 2 with a number of return bend Y so that there is a continuous circulation of water, entering through the pipe 20 and discharging through the pipe 21. Or several separate circulating pipes may be use Within the upper part of the concave space defined by the lining 17 there is located a bale 22 extending across and in line with the jets from the nozzles 15. The under surface of the baiile is depressed at the center with concave portions 23 at either side to divide the current and deflect it laterally against the concave lining 17, whence the mixed air and fuel pass sidewise and upward in two streams of wide cross-section into the combustion chamber where they spread against the water walls at the sides and ends. Such a distribution of the flame is more advantageous in that it is spread over a wider process of combustion and moves more slowly during this process than the long narrow jets` of flame proceeding from the ordinary nozzle burners.

Under certain conditions it may be desirable to admit a secondary supply of air near 5 the point where the stream emerges into the combustion chamber. In that case ducts 24, '25 and 26 may be provided in the sides and bottom of the baille through which air is forced by a blower to the furnace. These ducts are connected to a tubular passage 27 extending endwise through the baffle and communicating with supply pipes 28 (Fig. 2) at opposite ends. The baffle 22 may also be cooled b embedded pipes 29 extending longitudina ly and connected as shown in Fig. 2 with an inlet pipe 3() and Aan/outlet 1 pipe 31. Instead of cooling' the baille and the liner 17 with water, air or-other gases or, other fiuids may be used.

The burner 1s shown located inthe bottom wall of the furnace. It may, however, be installed in any one of the side walls and a numberI of lsuch burners may be installed in side walls or bottom wall or both. The burner may, if desired, be of other shapes than that illustrated.

While the invention is particularly advantageous in connection lwith a furnace lined with a water wall, because of the distribution of the radiant heat to`such wall,

it has advantages also in the regulated combustion and uniform mixture for other types of furnace. For example, in Fig. 3 we have shown such a burner applied inthe bottom wall of a furnace having only-ordinary side walls 32 of masonry. We have also in this figure shown the burner combined advantageously with the combined pulverizer and airV mixer of a previous application which we have filed No. 700,214, Patent No. 1,614,314. In this case the coal 33 passes from a chute to aspiral conveyor i 34 which feeds it at a regular rate to an air nozzle 35 thou h which air under pressure is continually Forced.` The mixture of air and coalv strikes a breaking plate 36 with such velocity that at least a considerable percentage of the coal is broken so fine as to be carried along with the air lcurrent through the mouth 37 at the top of the casing which constitutes a nozzle similar to the nozzle 15 of Fig. 1. The pieces oficoal which are -so large as to drop out of the air' extending across substantially the full width of the furnace. A baille 22'is located in line with the nozzle 37 and is similar in design and function tothe baille of Fig. 1.

Though we have described with great particularity of detail certain embodiments of our invention, yet it is not to be understood that the` invention is restricted to the particular embodiments disclosed. Various modifications thereof may be made by those skilled in the art without departing,from

Lthe invention as defined in the following claims.

What we claim is:

1. A furnace for burning powdered coal or the like comprising a main combustion chamber, a wall of the lfurnace being recessed, a nozzle for the fuel dischargin at the back of said recess and a baille in with and beyond the mouth of the nozzle and forming with the recessedk face Mof the wall a broad outlet passage which spreads the fuel into the main combustion chamberl in the form of broad streams of flaming gas.

ine

4. The furnace of claim 1, the' recessed portion 'of thewall being provided with passages for the circulation of a cooling fluid.

5. A furnace for 'burning powdered coal or the like comprising a lmam combustion chamber having a bottom wall which is recessed, a nozzle for the fuel discharging at the `back of said recess and a baille in line with and beyond the mouth of the nozzle' and forming with the recessed face of the wall a broad outlet passage which spreads the fuel into the main combustion chamber in the form of broad streams of flaming gas. 6. The furnace of claim 5, the baffle and recess extending continuously across practically the entire Width of the wall so as to direct the fueland air into the main combustion chamber in two'streams `at opposite sides of the baille and of practically the entire width 'of the wall.

7. The furnace ofclaim 5 having upright water tubes 'at the sides of the chamber l.exposed to the radiant heat of. the broad streams of flaming gas.

In witness whereof, we have slgned ourV names.

THOMAS E. MURRAY. JOHN H. LAWRENCE.

l. hereunto 

